1. Field
This disclosure relates to voice over data networks, more particularly to idle voice detection over data networks.
2. Background
As an alternative to a standard public switched telephone network (PSTN) telephone calls, some users place their calls across data networks. The data network phone call involves equipment that translates the voice traffic of the phone call into data packets and transmits the packets across the data network to be reassembled and translated back into voice at the other end. While data network calls may involve Voice over Frame Relay (VoFR), Voice over Asynchronous Transfer Mode (VoATM), Voice over Internet Protocol (VoIP) as well as other network protocols, for ease of discussion all of these will be referred to as VoIP.
In a VoIP call, a user picks up the handset of the phone. The equipment that will handle the VoIP call sends a dial tone to the user, who then dials the number of the receiving end. The network device involved in the sending end of the call will then map the phone number to an IP destination or IP next hop device) that will complete the call to the receiving phone. The presentation of dial tone and the transmission of touch tones provides the interface by which a human and the network device exchange signaling information. The two IP stations, the sending and the receiving ends, then establish a channel over the network, which may involve multiple hops or signaling exchanges through the IP network. The phone call then proceeds as a typical phone call. When either end of the call hangs up, the session ends. Generally, the calling end, also referred to as the originating or sending station, relies upon a termination signal from the called end, also called the receiving or terminating end. In some instances, because of signaling adaptation, the terminating end may not send the termination signal, or the signal is not interpreted correctly at the various pieces of equipment between the two ends of the call. Generally, this occurs because inband traffic (bearer traffic) in a phone call (Voice) over data network is not monitored. The equipment just passes packets of voice data between the two stations; it does not analyze the content of the Voice data packets.
This may cause billing issues, because the local telephone company may charge the VoIP provider for a non-revenue generating call. The measured duration of a VoIP call leg may not match the duration of a PSTN call leg because the signaling is not propagated or interpreted correctly. This results in a discrepancy in billing records that must be resolved before usage can be billed. It may also lead to resource issues, as an actually idle port may be held out of the port pool as being unavailable. When there is no active conversation in progress on those resources. This leads to poor port utilization and results in system inefficiencies.
Therefore, it would be useful if a method and apparatus were available that could determine if a call were actually terminated and disconnect all legs associated with that call.